Say one day you're walking down the street, enjoying a nice cup of coffee and the sun shine, when you come across an iPhone without its owner. If the device has been placed in Lost Mode already the phone will give you the needed information to contact its owner, but what if you find the device before Lost Mode is activated or if the system hadn't been set up? There's a way for you to be a Good Samaritan, and that way's name is Siri.
Simply activate Siri on the phone -- this can be done even if the device is locked -- and ask Siri "who does this phone belong to." Siri will give you the owner's contact information from phone number to email depending on the users settings. Now you know exactly how to contact the phone's owner, earning yourself some karma in the process.
Thanks to OSX Daily for finding this tip.